Safety device for hypodermic needle or the like

ABSTRACT

A safety device for a hypodermic needle or for a similar instrument used in the clinical puncture of the skin comprises a sheath (6, 25 or 32) adapted to be connected to the needle (5, 21 or 33) or to a support (4 or 31) for the needle. The sheath is so connected in a first position (FIGS. 1A, 2A, or 3A) which permits normal use of the needle and can be placed, by movement relative to the needle (FIG. 1B or 3B) or by folding upon itself (FIGS. 2B and 2C) in a second position in which the needle is encapsulated by the sheath. The sheath is retained in that second position, for example by a projection (9, 27 or 35) extending into a slot (10 or 36) or through an aperture (28).

This is a continuation of Ser. No. 08/160,859 filed Dec. 3, 1993, whichis a continuation of Ser. No. 07/709,999 filed Jun. 4, 1991, which acontinuation of Ser. No. 07/595,664 filed Oct. 11, 1990 (now U.S. Pat.No. 5,084,030), which is a continuation of Ser. No. 07/241,256 filedSep. 7, 1988 (now abandoned), which is a continuation of Ser. No.06/888,376 filed Jul. 23, 1986 (now U.S. Pat. No. 4,826,490).

The present invention is a safety device for a hypodermic needle orsimilar instrument used in the clinical puncture of the skin.

The taking of blood samples from persons in hospitals, health centres orother clinical areas is a routine medical procedure, as is the injectionof pharmaceutical preparations of biological materials. However, manyincidents have been reported in the press and in medical journals ofclinical operators subsequently accidentally wounding themselves orother persons with the needle and thereby either transmitting a diseaseor causing chemical or biological poisoning.

There is a clear need for a device which permits the disposal of ahypodermic needle or such instrument in a manner which protects theclinical operator, observers of the clinical procedure and all otherpersons concerned, including the general public, from accidentalwounding.

It is an object of the present invention to provide such a device.

The safety device according to the invention for a hypodermic needle orsimilar instrument comprises a sheath, adapted to be connected to saidneedle or other instrument or to a support therefor in a first positionwhich permits normal use of said needle or other instrument and to beplaceable, by movement relative to the needle or other instrument or byfolding upon itself, in a second position in which the needle or otherinstrument is encapsulated by the sheath and the sheath is retained inthat second position.

As indicated, the safety device of the present invention is generallyapplicable to the protection of puncturing instruments typified byhypodermic needles, although among such instruments hypodermic needlesare by far the most widely used. For example, the device may be appliedto the protection of biopsy needles, winged needles, that is needlesprovided with lateral attachments to enable them to be affixed to theskin surface as by adhesive tape, and to intravenous cannulas and lumbarpuncture needles. For convenience, the invention is hereinafterdescribed specifically as applied to "needles", in particular hypodermicneedles, but it is emphasised that the invention is not to be limitedthereby.

The sheath is adapted to be attached to the needle or to a support forthe needle but may be provided separately from the needle, to beattached to the needle or support at the point of use, either before orafter the needle has actually been used. It is much preferred that suchseparate sheaths be attached before use, so that the needle may be morereadily encapsulated immediately after it has been used. However, thesheath according to the present invention is preferably and convenientlysupplied already attached to the needle. In particular, it is preferablyattached either irremovably or in a way which makes its removaldifficult. For example, the sheath may be adhered to the needle or to asupport for the needle or may be clipped to the needle or support.

When the needle is designed for use without a syringe or remote from anassociated syringe, to which it is then linked by a flexible tube, thenthe sheath is preferably secured direct to the needle. The sheath maythen conveniently incorporate one or more parts which are foldablerelative to the body of the sheath and thereby to encapsulate theneedle.

When the needle, on the other hand, is mounted upon a housing designedto be attached to a syringe barrel or luer connector, then the sheathmay advantageously be secured to the housing. The sheath may then becapable of movement relative to the housing in a direction which has acomponent parallel to the length of the needle, so that the sheath maybe moved along the length of the needle until the latter is fullyencapsulated. This relative movement of sheath and housing may forexample be a linear sliding movement or a spiral movement, as moreparticularly exemplified hereinafter in FIGS. 3A and 3B of the drawings.

Such relative movement of sheath and housing may be determined by one ormore linear or spiral grooves or channels in the housing engaging one ormore lugs or other projections on the sheath--or grooves or channels inthe sheath engaging projections on the housing.

In the second position of the sheath, in which the needle isencapsulated, the sheath is retained against further movement relativeto the needle. That retaining of the sheath is preferably irreversibleor reversible only with difficulty. For example, one or more lugs orother projections on one of the relatively movable components may engageone or more apertures or slots in the other component, preferably underthe pressure of a natural resilience in at least one of the componentsor under pressure from one or more springs.

The sheath may advantageously and conveniently be made from a resilientplastics material, for example polypropylene, and the housing may bemade from the same, or a similar, material.

The invention will now be further described with reference to theaccompanying drawings, wherein:

FIG. 1A is a sectional view of a first embodiment of the safety deviceaccording to the present invention, in a position in which the needlemay be used normally;

FIG. 1B is an enlarged detailed view of the circled portion of FIG. 1A;

FIG. 2A is a view corresponding to that of FIG. 1A but with the sheathmoved to encapsulate the needle;

FIG. 2B is an enlarged detailed view of the circled portion of FIG. 2A;

FIG. 3 is a sectional view of a second embodiment of the safety deviceaccording to the present invention, in a position in which the needlemay be used normally;

FIG. 4A is a view corresponding to that of FIG. 3 but with the sheathfolded to encapsulate the needle;

FIG. 4B is an enlarged view of the circled portion of FIG. 4A;

FIG. 4C is a plan view of the device in the position shown in FIG. 4A;

FIG. 5A is a view, partly in section of a third embodiment of the safetydevice according to the present invention, in a position in which theneedle may be used normally;

FIG. 5B is a view corresponding to that of FIG. 5A but with the sheathmoved to encapsulate the needle;

FIG. 5C is an enlarged view of the circled portion of FIG. 5B.

The embodiment of the invention shown in FIGS. 1A and 1B comprises aneedle housing 4 in the form of a plastics moulding carrying a needle 5and, slidably supported upon the housing 4, a plastics sheath 6incorporating a thumbguard 7 integral therewith.

Also incorporated in the housing 4 and running length-wise, is a channel8. The sheath 6 incorporates a self-springed spigot 9 which slides alongthe channel 8, as shown in more detail in the enlarged inset. When thesheath travels to the end of the channel 8, the self-springed spigot 9drops into a small "well" 10, thus locking the sliding sheath inposition. The length of the sheath is such that, when it is locked inposition, the sharp end of the needle is completely enclosed by thesheath, as shown in FIG. 1B.

The housing 4 is designed to mate with any standard syringe barrel orluer connector. After use, the protective sheath is extended into thelocked position, thus encapsulating the needle in a safe manner.

The embodiment of the invention shown in FIGS. 2A to 2C is designed toallow encapsulation of a hypodermic needle 21 which is tethered to asyringe (not shown) by an extension tube 22. The needle 21 is sandwichedbetween two plastics mouldings or pressings 23,24 which together form asheath 25. A part 26 of the sheath 25 is permanently attached to thehypodermic needle. At points 23a and 24a the plastic is formed in amanner which allows the free ends of members 23 and 24 to hinge asindicated. Near to its outer end, the member 23 carries two spigots 27,which are designed to mate with holes 28 in the member 24 (when thesheath is in its folded position) and lock the sheath securely aroundthe needle 21.

The third embodiment of the invention, as illustrated in FIGS. 3A and3B, comprises a needle housing 31 in the form of a plastics moulding, aplastics sheath 32 which is free to rotate thereon and a needle 33.Impressed into the housing 31 is a helical groove 34 extending from nearthe end of the housing 31 which is distal to the needle 33 towards theneedle. The sheath 32 has a self-springed spigot 35 which fits into, andis free to move along, the helical groove 34. As shown in FIG. 3B,rotation of the sheath 32 in a clockwise direction (viewed from therear) will result in a forward motion causing the sheath to encapsulatethe needle 33. At the end of its travel the springed spigot 35 dropsinto a "well" 36 thereby locking the sheath in position. The length ofthe sheath 32 is such that when it has reached this locked position theneedle is completely encapsulated and withdrawn beyond the orifice 37 inthe outer end of the sheath.

The device shown in FIGS. 3A and 3B is designed to mate with anystandard syringe barrel or luer connector. After use, the protectivesheath is placed in position by applying a twisting force to the sheath.To facilitate the application of this twisting force, a raised section38 may be incorporated into the sheath's surface.

This form of the invention may be fabricated with one or more helicalgrooves, which may extend in a clockwise or anti-clockwise direction.For greater mechanical strength and stability, a double helix may bepreferred.

We claim:
 1. Clinical apparatus operably applicable to a patient by wayof a skin puncture, comprising:an elongate body defining a longitudinalpassageway therethrough for transfer of fluid relative to a patient, andhaving a first connector formation at one end thereof, said formationincluding a first abutment surface extending transversely of saidpassageway; in combination with: a disposable non-reusable needleassembly operable to effect said skin puncture and comprising: a needlesupport housing; a hollowed needle fixedly mounted in said housing toform with said housing a sub-assembly, with one end portion of saidneedle projecting from said housing; a sheath surrounding said needleand mounted directly on said sub-assembly for relative movement in thelongitudinal direction of said needle from a first position in whichsaid needle one end portion is exposed to effect said puncture, to asecond position in which said needle one end portion is enclosed withinsaid sheath; a locking mechanism including first and second elements,said first element being a projection from one of said housing andsheath, said second element being a stop surface defining a recess inthe other of said housing and sheath, said elements each extendingtransversely of said needle longitudinal direction, said elements beingspaced apart in said longitudinal direction when said guard is in saidfirst position, said projection being subject to a bias force actingbetween said housing and sheath during said relative movement, and saidprojection being automatically irreversibly moved into said recessalongside said stop surface in response to said bias force when saidsheath is in said second position to inhibit a returning relativemovement thereof towards said first position; and a second connectorformation at one end of said assembly, said second connector formationincluding a second abutment surface extending transversely of saidneedle longitudinal direction; said apparatus and assembly beingseparably interconnected for use by way of said first and secondconnector formation, with said first and second abutment surfacesmutually engaged and effective to constrain said sheath from movementtowards and around said apparatus.
 2. Clinical apparatus in combinationwith a needle assembly, said apparatus being operably applicable to apatient by way of a deliberate skin puncture, and said needle assemblybeing operable to effect said skin puncture, whereinsaid apparatuscomprises: an elongate body defining a longitudinal passagewaytherethrough for transfer of fluid relative to a patient, and having afirst connector formation at one end thereof, said formation including afirst abutment surface extending transversely of said passageway; saidassembly comprises: a support structure; a needle fixedly mounted insaid structure to form therewith a sub-assembly, with one end portion ofsaid needle projecting from said structure, and said one end portionterminating in a skin-puncturing tip; a guard mounted around part ofsaid sub-assembly for movement relative thereto in the longitudinaldirection of said needle from a first position in which said tip isexposed to effect said deliberate puncture, to a second position inwhich said tip is embraced by said guard to prevent unintended skinpuncture; a locking mechanism including first and second elements, saidfirst element being a projection from one of said sub-assembly andguard, said second element being a stop surface defining a spacebordering the other of said sub-assembly and guard, said elements eachextending transversely of said needle longitudinal direction, saidelements being spaced apart in said longitudinal direction when saidguard is in said first position, said projection being subject to a biasforce acting between said sub-assembly and guard during said relativemovement, and said projection being automatically irreversibly movedinto said space alongside said stop surface in response to said biasforce when said guard is in said second position to inhibit a returningrelative movement thereof towards said first position; and a secondconnector formation at one end of said needle assembly, said secondconnector formation including a second abutment surface extendingtraversely of said needle longitudinal direction; and said apparatus andassembly being separably interconnected for use by way of said first andsecond connector formations, with said apparatus held outside saidneedle, and with said first and second abutment surfaces mutuallyengaged and effective to constrain said guard from movement towards andaround said apparatus.